Deep Peroneal Research Articles

Contribution of Adenosine A2A Receptors in the Rostral Ventrolateral Medulla to Acupuncture Modulation of Hypertension

Acupuncture is used to manage high blood pressure (BP) in clinical practice. However, the mechanisms underlying its hypotensive effects remain unclear. Our previous studies have shown that electroacupuncture (EA) at the ST36‐37 acupoints, overlying the deep peroneal nerve, attenuates pressor responses through adenosine A2A receptors (A2AR) in the rostral ventrolateral medulla (rVLM). A2AR activation in the rVLM is associated with the upregulation of nitric oxide synthase (NOS) that contributes to sympathoinhibition and BP reduction. However, it is uncertain whether rVLM A2AR contributes to EA’s action in lowering high BP in sustained hypertension (HTN) in the rVLM. We hypothesized that EA lowers BP in HTN through adenosine A2AR mechanisms associated with the upregulation of neuronal NOS (nNOS) in the rVLM. The nNOS derived NO has been shown to exert central effects on BP. To mimic essential HTN in the clinic, we performed EA in conscious Dahl salt‐sensitive hypertensive rat (DSHR). EA (0.1‐0.4 mA, 2 Hz) was applied at ST36‐37 for 30 min twice weekly for four weeks while sham‐EA was conducted with the same procedures as EA except for no electrical stimulation. Elevated BP was reduced by EA (n=10) but not sham‐EA (n=8) and untreated ones (n=6). The A2AR level in the rVLM after EA treatment was increased (n=5; P < 0.05) compared to the sham‐EA (n=5). EA’s inhibitory effect on elevated BP was reversed transiently by unilateral microinjection of SCH 58261 (1 mM in 50 nl; an A2AR antagonist; n=7; P < 0.05) but not the vehicle (n=5) into the rVLM in EA‐treated DSHRs under anesthesia. Activation of rVLM A2AR in DSHRs treated with sham‐EA using an A2AR agonist, CGS‐21680 (0.4 mM in 50 nl; n=6), decreased BP. Furthermore, we found a co‐localization of A2AR with nNOS in the rVLM of DSHRs. The expression of rVLM nNOS was enhanced in DSHRs treated with EA compared to those treated with sham‐EA (n=5 in each group; P < 0.05). These data suggest that adenosine‐ A2AR in the rVLM contributes to EA’s inhibitory effect on elevated BP in sustained HTN, which is likely relevant to the upregulation of nNOS.

Nerve branches to the anterior tibial artery: Clinical application

Arteries receive vascular branches (VBs) from peripheral nerves. VBs are thought to be involved in arterial constriction. Although the anterior tibial artery (ATA) receives VBs, information on their branching patterns and distribution areas remains limited. The aim of this study was to investigate the anatomical structures of the VBs reaching the ATA. Forty cadaver limbs were examined to assess the branching patterns and distribution areas of the VBs reaching the ATA. The VBs reaching the ATA ramified from the deep fibular nerve (DFN), and the ATA received two or three VBs in each limb. The following mean distances from the head of fibula to the points at which the VBs reached the ATA were measured: all the VBs, 1st VB, 2nd VB and 3rd VB. The measurements were 51.5 ± 23.2 mm, 33.3 ± 3.7 mm, 53.3 ± 18.6 mm, and 72.2 ± 24.5 mm, respectively. In all limbs, the DFN and the ATA converged after the DFN branched into the 1st VB. The 2nd VB in 38 of 40 limbs and the 3rd VB in 20 of 32 limbs were distributed in the ATA proximal to the convergence point of the ATA and the DFN. These findings revealed that all VBs reaching the ATA ramified from the DFN in all limbs. The ATA received two or three VBs, and all the 1st VBs distributed to the ATA proximal to the convergence point.

Minimally Invasive Surgical Approach for Open Common Peroneal Nerve Neurolysis in the Setting of Previous Posterior Schwannoma Removal

The common peroneal nerve (CPN) runs laterally around the fibular neck and enters the peroneal tunnel, where it divides into the deep, superficial, and recurrent peroneal nerves. CPN entrapment is the most common neuropathy of the lower extremity and is vulnerable at the fibular neck because of its superficial location. Schwannomas are benign, encapsulated tumors of the nerve sheath that can occur sporadically or in cases of neurocutaneous conditions, such neurofibromatosis type 2. In cases with compressive neuropathy resulting in significant or progressive motor loss, decompression and neurolysis should be attempted. We present a technical note for the treatment of CPN compressive neuropathy in the setting of a previous ipsilateral schwannoma removal with a minimally invasive surgical approach and neurolysis of the CPN at the fibular neck.

Dorsalis pedis artery thrombosis in an elite rugby player: an unusual cause of pedal claudication in a high-risk ankle

Vascular thrombosis in young elite athletes is uncommon, usually affecting calf veins and arteries beyond the knee joint. Arterial thrombosis, especially in the dorsalis pedis artery, is very rare without premature atherosclerosis or trauma. Its clinical presentation with progressive claudication of insidious onset is nonspecific and overlaps with the symptoms of deep peroneal nerve compression as a part of anterior ankle impingement, a more common entity in athletes. Ultrasound can evaluate pedal claudication in athletes differentiating vascular and neural causes expediting diagnosis, management and, in turn, return to play. Furthermore, imaging-Doppler ultrasound and MR angiography in particular-plays a vital role in the evaluation of potential aetiology and evolution (i.e., collateral development and recanalization) of the occluded vessel. We present a case of dorsalis pedis artery thrombosis with both MRI and ultrasound findings in a professional rugby player who had no systemic comorbidity, but numerous previous surgical interventions around the ankle joint in both the remote and recent past, putting the adjacent DPA at increased risk for developing thrombosis. In this high-risk ankle, the dorsalis pedis thrombosis may be iatrogenic or due to sports-related, arterial wall injury with superimposed thrombosis.

Transfer of Soleus Muscular Branch of Tibial Nerve to Deep Fibular Nerve to Repair Foot Drop After Common Peroneal Nerve Injury: A Retrospective Study.

ObjectiveCommon peroneal nerve (CPN) injury that leads to foot drop is difficult to manage and treat. We present a new strategy for management of foot drop after CPN injury. The soleus muscular branch of the tibial nerve is directly transferred to the deep fibular nerve, providing partial restoration of motor function.MethodsWe retrospectively reviewed eight patients treated for CPN injury between 2017 and 2019. The soleus muscular branch of the tibial nerve was transferred to the deep fibular nerve to repair foot drop. Electrophysiology was conducted, and motor function was assessed. Motor function was evaluated by measuring leg muscle strength during ankle dorsiflexion using the British Medical Research Council (BMRC) grading system and electromyography (EMG).ResultsIn 10–15 months postoperatively, EMG revealed newly appearing electrical potentials in the tibialis anterior, extensor hallucis longus, and extensor toe longus muscle (N = 7). Two patients achieved BMRC grade of M4 for ankle dorsiflexion, 2 patients achieved M3, 1 patient achieved M2, and 2 patients achieved M1. Four patients showed good functional recovery after surgery and could walk and participate in activities without ankle-foot orthotics.ConclusionSurgical transfer of the soleus muscular branch of the tibial nerve to the deep fibular nerve after CPN injury provides variable improvements in ankle dorsiflexion strength. Despite variable strength gains, 50% of patients achieved BMRC M3 or greater motor recovery, which enabled them to walk without assistive devices.

Ultrasound of Small Nerves.

Nerve ultrasound has become an integral part of the diagnostic workup of peripheral neuropathies. Especially in the examination of small nerves, ultrasound provides superior image quality by using high frequency transducers. For a selection of small nerves, this article summarizes the local anatomy and common pathologies and offers simple instructions for determining their location with ultrasound including some cases with pathologies. This selection of nerves comprises the great auricular nerve, the supraclavicular nerves, the suprascapular nerve, the medial antebrachial cutaneous nerve, the lateral antebrachial cutaneous nerve, the palmar cutaneous branch of the median nerve, the long thoracic nerve, the intercostobrachial nerve, the posterior cutaneous nerve, the infrapatellar branch of the saphenous nerve, the medial calcaneal nerve, and the deep peroneal nerve at the ankle. Following our recommendations, these nerves can be swiftly located and tracked along their course to the site of the pathology.

Features of the Extraction of the Anterior Tibial Vessels in the Formation of Vascularized Bone Grafts

Background. The currently existing techniques for dissection the anterior tibial vascular bundle in the proximal third of the lower leg do not provide sufficient length of the vascular pedicle to rotate the tibial bone graft to the level of the middle third of the thigh.
 The aim of the study to substantiate the possibility of pedicled transfer to the level of the thigh middle third of two blood-supplied bone autografts on a common permanent pedicle, including the anterior tibial vascular bundle.
 Material and Methods. The study was conducted on 62 lower limbs of non-fixed (native) corpses. We studied the topographic and anatomical relationship between the anterior tibial vascular bundle and the deep peroneal nerve at the level of the proximal third of the leg.
 Results. The distance between the tip of the greater trochanter of the femur and the distal edge of the anterior tibial bone graft using a combination of grafts at the same level in men was Me 176.7 [173.7; 193.9] mm, in women Me = 151.6 [146.9; 159.9] mm. An analysis of limb lengths ratios in men and women indicates standard level that can be achieved with graft rotation in each person.
 Conclusion. Dissection of the anterior tibial vascular bundle at the level of the proximal third of the lower leg allows rotation of the complex of the anterior tibial bone autograft and the autograft of the second metatarsal bone into the area of the middle third of the femur on a single vascular bundle. Prevention of injury to the deep peroneal nerve branches during dissection of the vascular pedicle requires the use of microsurgical techniques and preoperative preparation.

Sonographic Evaluation of Site Specific Nerve Dimensions in Young Asymptomatic Adults: A Cross-sectional Study

Introduction: Tibial Nerve (TN) and Common Peroneal Nerve (CPN) supply the muscles and skin of lower extremity via their major branches and also send articular branches to the joints of lower extremity. Knowledge of nerve dimensions is useful for diagnosis of pathologies, planning nerve blocks, biopsies or other therapeutic procedures. Aim: To assess bilateral TN and Deep Peroneal Nerve (DPN) morphology and morphometry at ankle through a sonographic evaluation. Materials and Methods: A cross-sectional, observational study was conducted in the Department of Anatomy, King George’s Medical University, Lucknow, Uttar Pradesh from September 2018 to August 2019. Morphology and morphometry of TN and DPN was observed by High Resolution Ultrasonography (HRUS) at specific anatomical site in 100 first year Bachelor in Medicine and Bachelor in Surgery (MBBS) students. (50 males and 50 females). The nerve parameters like, Cross-sectional Area (CSA), nerve perimeter and depth from skin were measured and the data was analysed statistically. Among asymptomatic subjects, various nerve parameters and subcutaneous depth were observed in both genders to establish normal reference values for the purpose of creating database. The association of nerve parameter to BMI was also studied. To compare the change in a parameter at two different time intervals, paired t-test was used. To test the significance of two means, the student t-test was used. Results: Amongst the total 100 subjects(50 males and 50 females, age range: 17-25 years) included in the study, Mean CSA, perimeter and subcutaneous depth of right TN were 9.70±1.73 mm2, 9.91±1.57 mm and 9.62±0.94 mm; whereas mean CSA, perimeter and subcutaneous depth of left TN were 9.30±1.40 mm2, 9.36±1.46 mm and 9.33±0.95 mm. Mean CSA, perimeter and subcutaneous depth of right DPN were 7.00±1.60 mm2, 8.41±1.27 mm and 8.46± 0.93 mm whereas those on left side were 6.70±1.40 mm2, 6.81±1.39 mm and 8.50±0.68 mm.The CSA and perimeter of right TN was significantly (p 0.004) greater than left. DPN mean CSA (p-value 0.008) and perimeter (p<0.001) were significantly greater on the right side in comparison to left the TN was significantly deeper in location in females (p<0.004). DPN was significantly deeper in females than males (p<0.001). Differences in nerve parameters among subjects in relation to Body Mass Index (BMI) were insignificant. Conclusion: Nerve parameters were conveniently measured by ultrasound. Knowledge of site-specific normal size of nerves is of great importance in diagnosing various neuropathies, compression syndromes and traumatic nerve lesions. In current study, we have attempted to create a reference database that may be valuable for neurologists as well as radiologists. Knowledge of nerve depth & location may help in guiding ankle blocks in various surgeries and for other diagnostic and therapeutic purposes.

Harvester’s palsy – bilateral common peroneal nerve palsy: A descriptive case report

Peroneal neuropathy is the common mononeuropathy of the lower extremities in adults. The documented etiologies for peroneal nerve injury include trauma, traction, and external compression. Fibular neck is the most common site of common peroneal nerve (CPN) injury as the nerve lies superficial and vulnerable for injury. A 50-year-old male presented with foot drop in his left leg after working in squatting position for prolonged hours along with sensory disturbance in dorsum of left foot. Clinical examination showed poor dorsiflexion in both side ankle with preserved plantar flexion. Electrophysiological findings locate the site of lesion to be CPN at the level of fibular neck. We conclude that CPN is injured due to knee flexion in farmers repeatedly squatting for long hours. Superficial peroneal nerve may be spared due to their interfascicular arrangement at the level of fibular neck placing deep peroneal nerve near the fibula making them more susceptible to compression type of injury. Peroneal nerve may be damaged at multiple sites including ankle. The condition can be reversed with conservative treatment, primarily by avoiding the precipitating position.

Improvement of Motor Nerve Regeneration Using the Nanofibrils Technique in Adult Mongrel Dogs

The dog was selected as the experimental animal due to the fact that the larger the animal, the higher the regenerative power which depends mainly on the size of the nerve in use. Nine adult mongrel dogs were included in this study which aimed at evaluating motor nerve regeneration using nanofibrils technique for the purpose of developing a rationale for a minimal morbidity. A one and half cm gap was made in the common peroneal nerve by the direct cutting of both sides (proximal cut and then distal to avoid the double shock). The nanofibrils were used to fill the space and cover the two fixed ends in six of the dogs and another three animals were used as control. The nerve was cut and the space in between the two fixed ends was left without nanofibrils. Four months after surgery, the regenerated nerves were evaluated by macroscopic and microscopic examination. Normal segments of the deep peroneal nerve (D.P.N.) were taken to compare the changes. All animals with implanted nanofibrils used their limbs successfully at 3-4 weeks, the animal gait returned to its normal condition without any remarkable symptoms of lameness and the joints angles displayed its normal posture. Dogs in the control group showed lameness and flexion of the upper joints all-over during the time of the experiment with marked atrophy of the limb muscles. Better organized histological structures of nanofibre in treated nerve samples than the untreated control one were noted. More compartmentation of well-differentiated myelinated nerve fibers into several small nerve bundles in nanofibre treated nerve trunks compared with fewer bundles in the untreated control group. Connective tissue stroma (epineurium, perineurium and endoneurum) were more prominent with relatively higher numbers of small blood vessels compared with the untreated control group. Thus we concluded that nanofibres can be regarded as an efficient regeneration enhancing material in peripheral nerve injuries.

Limb Muscle Reinnervation with the Nerve-Muscle-Endplate Grafting Technique: An Anatomical Feasibility Study.

Background Peroneal nerve injuries results in tibialis anterior (TA) muscle paralysis. TA paralysis could cause “foot drop,” a disabling condition that can make walking difficult. As current treatment methods result in poor functional recovery, novel treatment approaches need to be studied. The aim of this study was to explore anatomical feasibility of limb reinnervation with our recently developed nerve-muscle-endplate grafting (NMEG) in the native motor zone (NMZ). Methods As the NMEG-NMZ technique involves in nerves and motor endplates (MEPs), the nerve supply patterns and locations of the MEP bands within the gastrocnemius (GM) and TA muscles of rats were investigated using Sihler's stain and whole-mount acetylcholinesterase (AChE) staining, respectively. Five adult rats underwent TA nerve transaction. The denervated TA was reinnervated by transferring an NMEG pedicle from the ipsilateral lateral GM. At the end of a 3-month recovery period, maximal muscle force was measured to document functional recovery. Results The results showed that the TA was innervated by the deep peroneal nerve. A single MEP band was located obliquely in the middle of the TA. The GM was composed of two neuromuscular compartments, lateral (GM-l) and medial (GM-m), each of which was innervated by a separate nerve branch derived from the tibial nerve and had a vertically positioned MEP band. The locations of MEP bands in the GM and TA muscles and nerve supply patterns demonstrated that an NMEG pedicle can be harvested from the GM-l and implanted into the NMZ within the TA muscle. The NMEG-NMZ pilot study showed that this technique resulted in optimal muscle force recovery. Conclusion NMEG-NMZ surgery is feasible for limb reinnervation. Specifically, the denervated TA caused by peroneal nerve injuries can be reinnervated with a NMEG from the GM-l.

Conduit-assisted Allograft Neurorrhaphy for the Treatment of Intractable Lower Extremity Pain Due to Neuromas-in-continuity.

Background:We present a novel technique for the management of intractable lower extremity pain, due to neuromas-in-continuity of two peripheral nerves, through combined neurectomies proximal to the zone of initial injury and subsequent bridging utilizing an allograft-coupled conduit construct.Methodology:A retrospective chart review of 36 patients (18 women and 18 men) with recalcitrant nerve pain secondary to neuromas-in-continuity of two peripheral nerves following lower extremity trauma was conducted. Subjects underwent superficial peroneal nerve (SPN) to deep peroneal nerve neurorrhaphy (19 patients) or SPN to sural nerve neurorrhaphy (17 patients) proximal to the zone of initial injury. Patient demographics, comorbidities, procedure details, complications, and preoperative and postoperative pain assessments using a visual analog scale were evaluated.Results:Residual nerve pain from previous lower extremity trauma was included. Analysis of preprocedure and postprocedure visual analog scale scores demonstrated a mean decrease of 7.45 points (mean: pre 8.89, mean: post 1.44). All patients voiced satisfaction with postoperative ambulatory tolerance and pain relief at last follow-up (mean: 30.86 months).Conclusions:The sequelae of neuromas-in-continuity of the SPN, deep peroneal nerve, and sural nerves were noted to have significantly improved with proximal neurectomy and subsequent bridging utilizing a nerve allograft and conduit construct. We present this coaptation technique as a viable treatment option for reduction in neurogenic pain involving peripheral nerve injury of two dermatome distributions.

Open Reduction and Internal Screw Fixation of Transitional Ankle Fractures in Adolescents.

Surgical treatment of a triplane fracture is indicated if there is >2 mm articular displacement of the distal aspect of the tibia or if the fracture pattern is deemed unstable following closed reduction and casting. Preoperative planning (Step 1) involves the use of radiographs and computed tomography scans to determine accurate fracture classification, the intended reduction maneuver, possible blocks to reduction, and screw trajectory and length. Room setup and patient positioning (Step 2) include placing the patient in the supine position with a bump under the hip, as well as the placement of a ramp or stack of blankets under the affected limb and adequate general anesthesia with muscle relaxation to facilitate reduction. Incision and surgical exposure (Step 3) is performed with use of an anterior ankle incision at the anatomic plane between the extensor hallucis longus and extensor digitorum longus, protecting the neurovascular bundle (i.e., the anterior tibial artery and deep peroneal nerve). Open reduction and assessment of reduction (Step 4) begins by removing any soft tissue, such as the periosteum, that may be interposed in the fracture site precluding a reduction. The ankle is then put through internal rotation and dorsiflexion in order to reduce the fracture, utilizing direct visualization through the incision and fluoroscopy to verify reduction with <2 mm articular step-off. Screw placement (Step 5) typically involves a 2-screw construct, with 1 screw starting at the anterolateral distal tibial epiphysis aiming medially (and staying within the epiphysis) and a metaphyseal screw aiming from the anterior metaphysis to the posterior Thurston-Holland fragment. Closure and immobilization (Step 6) usually involve a layered skin closure, as no deep closure is necessary in most cases. A below-the-knee cast is applied with the ankle in neutral dorsiflexion. Nonoperative treatment typically involves closed reduction and long-leg cast immobilization. Surgical treatment with reduction and screw fixation of triplane fractures is indicated for patients with >2 mm articular displacement or >3 mm physeal displacement of the distal aspect of the tibia. Achieving and maintaining reduction with screw fixation within these tolerances helps decrease the chance of arthritis development by 5 to 13 years postoperatively5,7. Following treatment of a triplane fracture with reduction and screw fixation, full ankle range of motion and normal growth are anticipated. Postoperative follow-up continues until skeletal maturity or until 1 year postoperatively with evidence of continued growth by Park-Harris lines on sequential radiographs. Short-term recovery is expected to be excellent, and long-term results are expected to be good as long as <2 mm articular reduction is achieved and maintained5,7. General anesthesia with muscle relaxation helps with closed or open reduction.Computed tomography is valuable for determining the maximum articular displacement and for 3D surgical planning for screw trajectories.Be aware of the periosteum and perichondrial ring as possible soft-tissue blocks to reduction, and do not hesitate to visualize the periosteum with an open technique to achieve anatomic reduction. AITFL = anterior inferior tibiofibular ligamentAP = anteroposteriorCT = computed tomography.

Critical illness neuropathy in severe COVID-19: a case series.

IntroductionNeurological complications of SARS-CoV-2 disease have received growing attention, but only few studies have described to date clinical and neurophysiological findings in COVID patients during their stay in intensive care units (ICUs). Here, we neurophysiologically assessed the presence of either critical illness neuropathy (CIP) or myopathy (CIM) in ICU patients.Materials and MethodsPatients underwent a neurophysiological assessment, including bilateral examination of the median, ulnar, deep peroneal and tibial motor nerves and of the median, ulnar, radial and sural sensory nerves. Needle electromyography (EMG) was performed for both distal and proximal muscles of the lower and upper limbs. In order to differentiate CIP from CIM, Direct Muscle Stimulation (DMS) was applied either to the deltoid or tibialis anterior muscles. Peak to peak amplitudes and onset latencies of the responses evoked by DMS (DMSamp, DMSlat) or by motor nerve stimulation (MNSamp, MNSlat) were compared. The ratio MNSamp to DMSamp (NMR) and the MNSlat to DMSlat difference (NMD: MNSlat − DMSlat) were also evaluated.ResultsNerve conduction studies showed a sensory-motor polyneuropathy with axonal neurogenic pattern, as confirmed by needle EMG. Both MNSamp and NMR were significantly reduced when compared to controls (p < 0.0001), whereas MNSlat and NMD were markedly increased (p = 0.0049).ConclusionsWe have described COVID patients in the ICU with critical illness neuropathy (CIP). COVID-related CIP could have implications for the functional recovery and rehabilitation strategies.

Abstract MP23: Arterial Depressor Responses Induced By Neuromodulation Of Deep Peroneal Nerve In Spontaneously Hypertensive Rats

Hypertension affects nearly half of the US population but only 43% achieved blood pressure control with medication alone. Medical devices for hypertension include implantable lead electrodes that stimulate the carotid baroreceptors with promising results, albeit with significant adverse complications. To address these limitations, we have proposed the use of deep peroneal nerve stimulation (DPNS), which elicited a depressor response in anesthetized, breathing supported, spontaneously hypertensive rats (SHR). In this study, we further define the electrical stimulation parameters that optimize the DPNS depressor response, and demonstrated that increasing the pulse duration from 0.15 ms to 1ms, of 1.0 mA pulses at 2 Hz for 10 sec, significantly reduced the mean arterial pressure (MAP) by 8±4 mmHg (p&lt;0.005; n=4) in this animal model. DPNS also caused an immediate increase in renal nerve activity (RNA; p&lt; 0.004, n=5), which may represent afferent sensory axons from the kidney, although this possibility needs to be further investigated. In a separate cohort of anesthetized SHR animals, breathing spontaneously, we demonstrated that optimal DPNS stimulation reduced the MAP from 121±3 to 108±4; p=0.02; n=10). To confirm if DPNS is able to evoke a depressor response in fully awake SHR animals, we developed a novel miniaturized wireless microchannel electrode (w-μCE) with a L-shaped microchannel, through which the DPN slides and locks into a recording/stimulation chamber, causing no discomfort to the animal during locomotion. Two weeks after implantation of the w-μCE neural stimulation device, animals were movement-retrained to received wireless DPNS for 10 min daily for 2 weeks. Blood pressure was measured by tail-cuff at baseline, 10 days after device implantation, and 1 and 2-hr 15 days after DPNS. After two weeks of DPNS, the acute neuromodulation treatment reduced the initial systolic BP of 154±20 mmHg to 127±7 and 119±2 mmHg at 1 and 2 hr; respectively (p&lt; 0.001, n=15-19 measurements; n=2 animals). These results provide evidence of the effectiveness and reliability of DPN neuromodulation as a possible treatment for drug-resistant hypertension.

Comparison of Sensory and Motor Innervation Between the Acupoints LR3 and LR8 in the Rat With Regional Anatomy and Neural Tract Tracing.

ObjectiveThis study aimed to investigate the sensory and motor innervation of “Taichong” (LR3) and “Ququan” (LR8) in the rat and provide an insight into the neural relationship between the different acupoints in the same meridian.MethodsThe LR3 and LR8 were selected as the representative acupoints from the Liver Meridian and examined by using the techniques of regional anatomy and neural tract tracing in this study. For both acupoints, their local nerves were observed with regional anatomy, and their sensory and motor pathways were traced using neural tract tracing with single cholera toxin subunit B (CTB) and dual Alexa Fluor 594/488 conjugates with CTB (AF594/488-CTB).ResultsUsing the regional anatomy, the branches of the deep peroneal nerve and saphenous nerve were separately found under the LR3 and LR8. Using single CTB, the sensory neurons, transganglionic axon terminals, and motor neurons associated with both LR3 and LR8 were demonstrated on the dorsal root ganglia (DRG), spinal dorsal horn, Clarke’s nucleus, gracile nucleus, and spinal ventral horn corresponding to their own spinal segments and target regions, respectively. Using dual AF594/488-CTB tracing, it was shown that the sensory and motor neurons associated with LR3 were separated from that of LR8.ConclusionThis study demonstrates that LR3 and LR8 are innervated by different peripheral nerves, which originated from or terminated in their corresponding spinal segments and target regions independently through the sensory and motor pathways. These results provide an example for understanding the differential innervation between the different acupoints in the same meridian.

Anatomic correlation of common fibular nerve palsy encountered after short leg casts

Objectives: Short leg casts are routine applications in orthopaedic practice. The aim of the study was to investigate the course of the common fibular nerve and its branches (deep and superficial fibular nerves) around the fibular neck in order to describe a convenient method for applying the lower extremity casts with low risk of fibular nerve entrapment. Methods: Fifty lower extremities of 26 cadavers were examined. The point where common fibular nerve itself or its branches (deep and superficial fibular nerves) crossed over the fibular neck were dissected. The points where the nerve or its branches have risk of compression between the fibula and the cast were investigated in relation to fibular length. Results: The average fibular length was 356.9±26.4 mm. The common fibular nerve did not pass over the fibular neck in any specimen, instead, its branches crossed over it. The average distance from the tip of the fibular head to deep fibular nerve and superficial fibular nerve were 42.9±6.5 mm and 52±6.3 mm, respectively. The mean ratio of fibular length to these distances were 8.5±1.2 and 7.0±0.8, respectively. Conclusion: As short knee casts is a frequent application in clinical practice, it is important to determine a safe upper border for the casts to protect common fibular nerve or its branches. We recommend that the upper border of short leg casts should not exceed the upper 1/7th of the fibular length of the patient in order to avoid fibular nerve palsy.

Association of Peripheral Neuropathy in Hepatitis C Infection with and without Cryoglobulineamia

Objective: The purpose of this study was to find out the association of peripheral neuropathy in hepatitis C infection with and without cryoglobulineamia. Study Design: Cross sectional study Place and Duration: Conducted in Liver Transplant Unit, Gambat Institute of Medical Sciences, Gambat Khairpur Mirs, Sindh for the duration of six months from November 2020 to April 2021. Methods: Total 50 patients who had hepatitis C infection and peripheral neuropathy were included in this study. Patients were aged between 18- 60 years. Detailed demographics of patients including age, sex and body mass index were recorded after taking informed written consent. When symptoms and evidence of peripheral sensory or motor involvement were evident, clinical neuropathy was diagnosed. Sural nerve biopsy was done on patients and the biopsy specimen was evaluated morphologically and morphometrically. Multiple neuropathy, cranial neuropathy, and polyneuropathy are all terms used to describe peripheral nerve involvement. Our research focused on the motor conduction of the median, ulnar, and common peroneal nerves, measuring MCV, CMAP amplitude, and distal latency (DL) in both patients with and without cryoglobulinaemia for each nerve. The SPSS 20.0 version was used to analyze the data. Results: Mean age of the patients was 46.23±9.87 years with mean BMI 29.16±11.27 kg/m2. There were 30 (60%) females and 20 (40%) were males. We found that 35 (70%) patients had CG involvement with peripheral neuropathy and 15 (30%) cases were without CG. Prevalence of polyneuropathy was higher 19 (54.3%) in CG patients as compared to non CG 2 (13.3%). Mononeuropathy or multiple neuropathy was higher in HCV CG patients 13 (37.1%) as compared to HCV non CG patients 4 (26.7%). 25 patients underwent nerve biopsy (20 CG patients and 5 non CG). Prevalence of epineurial vasculitis and fascicular loss of axons was higher in non CG patients while demyelination + axonal degeneration were prevalent in CG patients. MCV of the deep peroneal nerve in patients with CG+ was low as compared to CG. Even though no statistically significant differences were detected, the other neurophysiological measures pointed to a more extensive and severe involvement of peripheral nerve in CG+ patients. Conclusion: We concluded in this study that the association of peripheral neuropathy in HCV patients with cryoglobulinaemia was greater as compared to non-CG HCV patients. It appears that both CG+ and CG patients suffer from peripheral nerve injury via a vasculitic mechanism, as evidenced by clinical and morphological observations. Serum CG levels indicate a more severe and broad neuropathic involvement, however research suggests that cryoglobulins are not the only element in the vasculitic process. Keywords: Cryoglobulinemia, Peripheral Neuropathy, HCV

Is denervation surgery possible in the treatment of hallux rigidus? An anatomic study of cadaveric specimens.

The aim of this study was to provide anatomic considerations in the first metatarsophalangeal joint (FMPJ) innervation and to evaluate the feasibility of the denervation surgery in the treatment of hallux rigidus. In this cadaveric study, 14 fresh frozen cadaveric transtibial amputation specimens was used. For nerve dissection, dorsal and plantar longitudinal incision centered over the FMPJ were performed. Deep peroneal and dorsomedial cutaneous nerves were dissected in the dorsal aspect of the joint. Medial plantar nerve branches, medial and lateral hallucal nerves, were dissected in the plantar aspect of the joint. The presence, number, and location of articular branches to the FMPJ capsule were recorded. Dorsal and plantar incision length for proper dissection were also recorded. Nerve dissection of the 14 specimens revealed the following number of articular branches from the relevant nerves: 14 from dorsomedial cutaneous nerves, 11 from deep peroneal nerves, 6 from medial hallucal nerve, and 5 from lateral hallucal nerve. Dorsal incision mean length was 60.53 (range, 42.48-85.12) mm, and the plantar incision mean length was 88.08 (range, 77.32-111.21) mm. Evidence from this study has shown that partial dorsal denervation of the FMPJ may be a technically feasible procedure along with the presence of superficially easily dissected nerves with relatively small incision. Level 5.

Peripheral nerve adaptations to 10 days of horizontal bed rest in healthy young adult males.

Space analogs, such as bed rest, are used to reproduce microgravity-induced morphological and physiological changes and can be used as clinical models of prolonged inactivity. Nevertheless, nonuniform decreases in muscle mass and function have been frequently reported, and peripheral nerve adaptations have been poorly studied, although some of these mechanisms may be explained. Ten young healthy males (18-33 yr) underwent 10 days of horizontal bed rest. Peripheral neurophysiological assessments were performed bilaterally for the dominant (DL) and nondominant upper and lower limbs (N-DL) on the 1st and 10th day of bed rest, including ultrasound of the median, deep peroneal nerve (DPN), and common fibular nerve (CFN) , as well as a complete nerve conduction study (NCS) of the upper and lower limbs. Consistently, reduced F waves, suggesting peripheral nerve dysfunction, of both the peroneal (DL: P = 0.005, N-DL: P = 0.013) and tibial nerves (DL: P = 0.037, N-DL: P = 0.005) were found bilaterally, whereas no changes were observed in nerve ultrasound or other parameters of the NCS of both the upper and lower limbs. In these young healthy males, only the F waves, known to respond to postural changes, were significantly affected by short-term bed rest. These preliminary results suggest that during simulated microgravity, most changes occur at the muscle or central nervous system level. Since the assessment of F waves is common in clinical neurophysiological examinations, caution should be used when testing individuals after prolonged immobility.